Bad question, because it is two questions that the OP treats as related (regret vs possibility to have done something differently in the past), but that are act

Bad question, because it is two questions that the OP treats as related (regret vs possibility to have done something differently in the past), but that are actually not. For example, let's suppose that the answer to the question about the biggest regret is "not learning to swim while still a child" (I learned while being 31 years old), but the reason is that my mother could not teach me and actively opposed any other possibility for me to learn. This was not something I could change about my past, even in theory.